Hi there
I am running a GL-MT3000 which is connected to a specific exit node on my tailnet. The exit node is approved; so client devices to GL-MT3000 properly have traffic forwarded through this exit node with no leaks detected.
The tailscale exit node is in a remote location from my VPN router. IP masquerading ALL on 0.0.0.0 is enabled via iptables; no trouble here.
DNS resolution was a little rusty at first but I dealt with this via manually setting the DNS server on the router to use encrypted 8.8.8.8. By rusty, I mean that DNS resolution was exceedingly slow; since I was relying on unbound on my exit node to resolve DNS queries from client devices for the vpn router. I resolved this fully yesterday.
My main issue right now is that client devices connected to the GL router will intermittently lose internet access. I've seen this a few times; and with another device connected to a different WAN (but still connected via tailscale), I can SSH to my exit node, perform ping, curl, and so on, so I don't think the WAN that my exit node relies on is to blame (it's a residential commercial ISP).
My main question is which diagnostic checks can I perform with my current topology? Other than verifying iptables, DNS resolution, SSH access, ICMP and so on from the exit node; how do I actually figure out what's causing the internet to drop intermittently like this? Do I probe the router someplace? Or from my client devices connected via WLAN to it? It's a bit of a head scratcher; but in its present state, these intermittent drops are no good. It's not just a few seconds; it drops for several minutes. This doesn't work for a lot of my use-cases.